The idea of building a bridge across the English Channel put forward by UK Foreign Secretary Boris Johnson last month has prompted the French company that runs the Channel Tunnel to open a dialogue with the UK government.
Such a bridge would need to be taller than the world’s tallest, the Millau Viaduct in France (pictured), but Eurotunnel chief executive Jacques Gounon has written to UK Prime Minister Theresa May to say he was very interested in the proposal.
Furthermore, Eurotunnel says it has first rights to build a fixed link.
"The idea of a second fixed link is something that we regularly consider in our long-term plans and we would be delighted to engage with your officials to explore the possibility further," he wrote, reports The Sunday Telegraph.
And a spokesperson for the company claimed Eurotunnel has first refusal on a second fixed link.
"As part of the Treaty of Canterbury and the Concession Agreement which established the Channel Tunnel, Eurotunnel has the right to build the next fixed link," he said. "Because of this we have written to the government and said ‘let’s have a chat’."
Johnson’s idea of a cross-Channel bridge was widely dismissed as an economic impossibility and an engineering liability.
"Building a huge concrete structure in the middle of the world’s busiest shipping lane might come with some challenges," said the UK Chamber of Shipping.
Although longer bridges have been built – the Danyang-Kunshan Grand Bridge in the Yangtze delta is 165km long – a Channel version would have to include a suspension bridge able to accommodate 80m-high ships.
Such a bridge would need towers more than 500m high, said Wanda Lewis, Professor of Structural Engineering at the University of Warwick.
The tallest mast in the world is the Millau Viaduct (pictured) in France at 343m – but this was build on terra firma.
A more likely choice would be a second tunnel, or possibly a combined bridge and tunnel – largely because the cost would be a small fraction of the £120bn estimate for a bridge. Here the economic case is stronger, because the existing link is nearing capacity and the growth in trade and travel between the UK and the EU may grow with their economies.
Although the idea of a bridge was put forward by Johnson during discussion with French president Emmanuel Macron as a way of binding the UK and France after Brexit, any developments in the project would probably have to wait until Westminster and Brussels reach a deal on Brexit.
If a worst-case scenario comes to pass, there may not be any need for a second link for quite some time.
Image: The Millau viaduct holds the record for mast height (YouTube)